Status codes
Status Codes metrics in the Cloudflare dashboard Analytics app provide customers with a deeper insight into the distribution of errors that are occurring on their website per data center. A data center facility is where Cloudflare runs its servers that make up our edge network (current locations ↗).
HTTP status codes that appear in a response passing through our edge are displayed in analytics.
The Origin Status Code can help you investigate issues on your origin. If your origin returns a 5xx error, Cloudflare’s edge will forward this error to the end user. Comparing the Edge Status Code and Origin Status Code can help determine whether the issue is occurring on your origin or on the Cloudflare edge.
Errors that originate from our edge servers (blank 502, 503, or 504 error page with just Cloudflare) are not reported as part of the error analytics.
You can filter out specific error(s) by selecting one or more in the legend. You can also exclude a particular error and it will no longer display as part of the graph.
400- Bad Request intercepted at the Cloudflare Edge (for example, missing or bad HTTP header)403- Security functionality (for example, Web Application Firewall, Browser Integrity Check, Cloudflare challenges, and most 1xxx error codes)409- DNS errors typically in the form of 1000 or 1001 error code413- File size upload exceeded the maximum size allowed (configured in the dashboard under Network > Maximum Upload Size.)444- Used by Nginx to indicate that the server has returned no information to the client, and closed the connection. This error code is internal to Nginx and is not returned to the client.499- Used by Nginx to indicate when a connection has been closed by the client while the server is still processing its request, making the server unable to send a status code back.
For more information, refer to 4xx Client Error.
400- Origin rejected the request due to bad, or unsupported syntax sent by the application.404- Only if the origin triggered a 404 response for a request.4xx50x
For more information, refer to 4xx Client Error and Troubleshooting Cloudflare 5XX errors.
520- This is essentially a “catch-all” response for when the origin server returns something unexpected, or something that is not tolerated/cannot be interpreted by our edge (that is, protocol violation or empty response).522- Our edge could not establish a TCP connection to the origin server.523- Origin server is unreachable (for example, the origin IP changed but DNS was not updated, or due to network issues between our edge and the origin).524- Our edge established a TCP connection, but the origin did not reply with a HTTP response before the connection timed out.525- This error indicates that the SSL handshake between Cloudflare and the origin web server failed, either due to a network issue or a certificare issue at the origin.526- The certificate configured at the origin is not valid.
For more information, refer to Troubleshooting Cloudflare 5XX errors.